

const regexp =  /\w{5,}@\w+.\w+/ ;

console.log( regexp.test( 'hello@abc.xyz' ) );
console.log( regexp.test( 'abc@abc.xyz' ) );
console.log( regexp.test( '12345@163.com' ) );
console.log( regexp.test( '123456@qq.com' ) );
console.log( regexp.test( '123456@qq' ) );

const re = /^[A-Za-z]{1}\w{5,}@\w+(.com|.cn|.net|.com.cn|.net.cn|.edu.cn)$/

console.log( re.test( '123456@163.com' ) );
console.log( re.test( 'a23456@163.com' ) );
console.log( re.test( 'helloworld@kaifamiao.xyz' ) );

const telRegexp = /^(13\d{1}|15\d{1}|166|17\d{1}|188|198)\d{8}$/;

console.log( telRegexp.test( '13243211234' ) );
console.log( telRegexp.test( '15243211234' ) );
console.log( telRegexp.test( '19643211234' ) );
console.log( telRegexp.test( '1524321' ) );
console.log( telRegexp.test( '152432112345678' ) );
console.log( telRegexp.test( '17112345678' ) );